# Homework 1 - Part 1
def palindrome?(string)
	string = string.downcase.gsub(/\W/, '')
	string == string.reverse
end

def count_words(string)
	Hash[string.downcase.scan(/\w+/).group_by{|s| s}.map{|kv| [kv[0], kv[1].size]}]
end

# Homework 1 - Part 2
class WrongNumberOfPlayersError < StandardError ; end
class NoSuchStrategyError < StandardError ; end

def lose?(mine, his)
	mine.upcase!;  his.upcase!
	strategies = ['R', 'P', 'S']
	if(!strategies.include?(mine) or !strategies.include?(his))
		raise NoSuchStrategyError
	end
	
	["RP", "PS", "SR"].include?(mine + his)
end

def rps_game_winner(game)
	raise WrongNumberOfPlayersError unless game.length == 2
	
	if(lose?(game[0][1], game[1][1]))
		game[1]
	else
		game[0]
	end
end

def rps_tournament_winner(game)
	if(game[0][0].kind_of?(String))
		rps_game_winner(game)
	else
		rps_game_winner [rps_tournament_winner(game[0]), rps_tournament_winner(game[1])]
	end
end

# Homework 1 - Part 3
def combine_anagrams(words)
	words.group_by{|w| w.downcase.chars.sort.to_s}.values
end

# Homework 1 - Part 4
class Dessert
	def initialize(name, calories)
		@name = name
		@calories = calories
	end
	
	attr_accessor :name
	attr_accessor :calories

	def healthy?
		@calories < 200
	end

	def delicious?
		true
	end
end

class JellyBean < Dessert
	attr_accessor :flavor
	
	def initialize(name, calories, flavor)
		super(name, calories)
		@flavor = flavor
	end

	def delicious?
		@flavor != "black licorice"
	end
end

# Homework 1 - Part 5
class Class
	def attr_accessor_with_history(attr_name)
		attr_name = attr_name.to_s
		attr_reader attr_name
		attr_reader attr_name+"_history"
		class_eval %Q{
			def #{attr_name}=(value)
				if(!defined?(@#{attr_name}_history))
					@#{attr_name}_history = [@#{attr_name}]
				end

				@#{attr_name} = value
				@#{attr_name}_history << value
			end
		}
	end
end